FRISCO — It may be a little like the Dutch boy putting his finger in the leaky dike, but Colorado Forest Service officials are warning that transporting firewood from place to place may increase the spread of invasive tree-killing bugs.

Moving firewood even short distances increases the risk to Colorado’s native forests and urban trees. With the 2013 detection of the highly destructive emerald ash borer in the City of Boulder, and ongoing bark beetle epidemics in the state’s mountain forests, the Colorado State Forest Service wants to be sure people are aware of the risks associated with moving firewood. Continue reading “Is out-of-state firewood a threat to Colorado trees?”→

FRISCO — There’s a good reason that environmentalists have been called treehuggers from time to time — instinctively, some of us know how vital forests are to the health of the planet.

Now, some empirical research shows that’s true not just metaphorically, but that the loss of trees in the environment can have serious consequences for human health. The study by the U.S. Forest Service looked at the loss of more than 100 million ash trees in the East and Midwest.

Three years later, in 2009, after the invasive insect spread to the neighborhood. Photo courtesy Dan Herms, Ohio State University.

After analyzing 18 years worth of data from 1,296 counties in 15 states, researchers found that Americans living in areas infested by the emerald ash borer, a beetle that kills ash trees, suffered from an additional 15,000 deaths from cardiovascular disease and 6,000 more deaths from lower respiratory disease when compared to uninfected areas. When emerald ash borer comes into a community, city streets lined with ash trees become treeless.

“ There’s a natural tendency to see our findings and conclude that, surely, the higher mortality rates are because of some confounding variable, like income or education, and not the loss of trees,” said Geoffrey Donovan, a research forester at the Forest Service’s Pacific Northwest Research Station. “But we saw the same pattern repeated over and over in counties with very different demographic makeups.”

The researchers analyzed demographic, human mortality, and forest health data at the county level between 1990 and 2007. The data came from counties in states with at least one confirmed case of the emerald ash borer in 2010. The findings — which hold true after accounting for the influence of demographic differences, like income, race, and education—are published in the current issue of the American Journal of Preventive Medicine.

Although the study shows the association between loss of trees and human mortality from cardiovascular and lower respiratory disease, it did not prove a causal link. The reason for the association is yet to be determined.

The emerald ash borer was first discovered near Detroit, Michigan, in 2002. The borer attacks all 22 species of North American ash and kills virtually all of the trees it infests.

The study was conducted in collaboration with David Butry, with the National Institute of Standards and Technology; Yvonne Michael, with Drexel University; and Jeffrey Prestemon, Andrew Liebhold, Demetrios Gatziolis, and Megan Mao, with the Forest Service’s Southern, Northern, and Pacific Northwest Research Stations.

A close up of an Emerald Ash Borer insect and the feeding tunnels the insects create under ash bark. Insect Photo: David Cappaert, Michigan State University. Tunnel Photo: NPS Photo

By Summit Voice

SUMMIT COUNTY — The destructive emerald ash borer has made its first incursion into the backcountry of Great Smoky Mountains National Park, where it could do serious damage to hardwood forests, according to National Park Service biologists.

The ash borer is a non-native species that was introduced from Asia and first discovered in southern Michigan in 2002. In just 10 years, the bugs have spread to 16 states and two Canadian provinces killing tens of millions of ash trees.